linux-kernel - Re: [PATCH] memcg: fix mutex not unlocked on memcg_create_kmem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 30 Jan 2014 13:09:52 -0800 (PST)
From:	David Rientjes <rientjes@...gle.com>
To:	Vladimir Davydov <vdavydov@...allels.com>
cc:	akpm@...ux-foundation.org, mhocko@...e.cz, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] memcg: fix mutex not unlocked on memcg_create_kmem_cache
 fail path

On Thu, 30 Jan 2014, Vladimir Davydov wrote:

> Signed-off-by: Vladimir Davydov <vdavydov@...allels.com>

Some changelog would be helpful since this fixes an issue already in 
Linus's tree.

Commit 842e2873697e ("memcg: get rid of kmem_cache_dup()") introduced a 
mutex for memcg_create_kmem_cache() to protect the tmp_name buffer that 
holds the memcg name.  It failed to unlock the mutex if this buffer could 
not be allocated.

This patch fixes the issue by appropriately unlocking the mutex if the 
allocation fails.

Acked-by: David Rientjes <rientjes@...gle.com>

That said, this tmp_name stuff seems totally unnecessary.  
kmem_cache_create_memcg() already does the kstrdup() so why not just pass 
in a pointer to already allocated memory for s->name rather than having 
this mutex or global buffer at all?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/